Selective oxidative modification of tryptophan and cysteine residues using visible light responsive Rh doped SrTiO3 photocatalyst
Abstract
Abstract In recent years, amino acids and peptides have attracted significant attention in food and medical fields due to their functionality. These functionalities largely depend on the chemical properties of their side chains, and efficient methods for selective side chain modification are desired. In this study, we investigated the selective modification of amino acids and peptides using rhodium-doped SrTiO3 (g-STO:Rh), a visible light-responsive photocatalyst. HPLC and LCMS analyses revealed that g-STO:Rh exhibited selective reactivity toward tryptophan and cysteine among the 20 protein-constituent amino acids. While cysteine was oxidatively dimerized to cystine, tryptophan underwent selective oxidation of its indole ring side chain, forming N-formylkynurenine. Furthermore, studies on dipeptides and tripeptides containing tryptophan have demonstrated that selective oxidation proceeds similarly to tryptophan residues within peptides.
Article Details
Authors (7)
Sho Usuki
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-0012, Japan
Naoko Taki
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-0012, Japan
Yuma Uesaka
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-0012, Japan
Haru Togawa
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-0012, Japan
Shanhu Liu
Henan Joint International Research Laboratory of Environmental Pollution Control Materials, Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering
Kenji Yamatoya
Kazuya Nakata
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-0012, Japan